Function to find duplicated columns in pandas dataframe

gistfile1.txt

def duplicate_columns(frame):
    groups = frame.columns.to_series().groupby(frame.dtypes).groups
    dups = []

    for t, v in groups.items():

        cs = frame[v].columns
        vs = frame[v]
        lcs = len(cs)

        for i in range(lcs):
            iv = vs.iloc[:,i].tolist()
            for j in range(i+1, lcs):
                jv = vs.iloc[:,j].tolist()
                if iv == jv:
                    dups.append(cs[i])
                    break

    return dups